Maths Spl

They are management programmes and hence you do not require maths at 10+2 level.

No, maths is entirely different from medical and bio courses. So, if you want to give medical exams you should take biology in 11 and 12th.

No, maths is not at all necessary for pursuing BBA. The subjects in +2 do not matter for BBA.

It is a little difficult, but yeah you may try.
Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges which provides you brochure:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india

Yes, you may try, but seems a little difficult.
Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges which provides you brochure:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india

Job roles in government central or state government department:
Banks.
Armed Forces are General in nature or Technical requiring first degree level of knowledge.
Government teaching and Research Indian Statistical Service.In universities or colleges in the government, or private sector.Technical or administrative in nature.
Teaching at the undergraduate/postgraduate level.Teaching in management, actuarial programs in the private sector.

No, it's not necessary as you are doing nursing.

It totally depends upon your interest. If you are interested, you can go for it and choose subject according to your choice, and before taking any subject, see if you can go good in future or not.

Do five year previous sample paper of every subject (Himani Publication or RG Publication). You can easily score 70% marks and above.
As far I know, in MDU copies are checked by some lecturer who are not of that field, a design field engineering professor checks physics answer sheet. So, basically what you need to do is write in good handwriting and 10 mark questions must be in 3 pages at least.